The move was announced by executive vice president and general manager Josh Byrnes in a statement Sunday night.
Clark batted .182 with four home runs and 11 RBIs in 36 games with the Diamondbacks this season. He hit .255 with 59 homers and 178 RBIs over parts of five seasons with Arizona.
Clark has 1,188 hits, 251 home runs and 824 RBIs in 15-plus major league seasons with Detroit, Boston, the New York Mets, the Yankees, Arizona and San Diego.
Clark, 37, was a clubhouse leader and significant contributor to the otherwise young 2007 Diamondbacks team that advanced to the NLCS. He left for the San Diego Padres in 2008, but later returned to Arizona and re-signed with the Diamondbacks.
He homered twice in Arizona's season opener but had only two home runs since then.
The team says a corresponding move will be made at a later date.
Clark mostly was a pinch hitter and late-inning defensive replacement this season. His release could clear up a logjam at first at Triple-A Reno with Josh Whitesell and newly acquired Brandon Allen.